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Thromb Haemost 1997; 78(03): 1150-1156
DOI: 10.1055/s-0038-1657702
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An Experimental Multiple-Organ Model for the Study of Regional Net Release/Uptake Rates of Tissue-type Plasminogen Activator in the Intact Pig

Christina Jern
1   The Heart and Lung Institute, Clinical Experimental Research Laboratory, Goteborg University, Göteborg
2   The Institute of Clinical Neuroscience, Department of Neurology, Göteborg University, Göteborg
,
Heléne Seeman-Lodding
3   The Dept of Anesthesiology, Sahlgrenska University Hospital, Göteborg University, Göteborg
,
Bjӧrn Biber
4   The Dept of Anesthesiology, Umeå University Hospital, Umeå, Sweden
,
Ola Winsӧ
3   The Dept of Anesthesiology, Sahlgrenska University Hospital, Göteborg University, Göteborg
,
Sverker Jern
1   The Heart and Lung Institute, Clinical Experimental Research Laboratory, Goteborg University, Göteborg
› Author Affiliations
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Publication History

Received 24 1997

Accepted after revision 12 May 1997

Publication Date:
12 July 2018 (online)

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Summary

Experimental data indicate large between-organs variations in rates of synthesis of tissue-type plasminogen activator (t-PA), which may reflect important differences in the capacity for constitutive and stimulated t-PA release from the vascular endothelium. In this report we describe a new multiple-organ experimental in vivo model for simultaneous determinations of net release/uptake rates of t-PA across the coronary, splanchnic, pulmonary, and hepatic vascular beds. In eleven intact anesthetized pigs, blood samples were obtained simultaneously from the proximal aorta, coronary sinus, pulmonary artery, and portal and hepatic veins. Plasma flows were monitored separately for each vascular region. Total plasma t-PA was determined by ELISA with a porcine t-PA standard. Regional net release/uptake rates were defined as the product of arteriovenous concentration gradients and local plasma flows. The net release of t-PA across the splanchnic vascular bed was very high, with a mean output of 1,919 ng total t-PA X min-1 (corresponding to 90 ng per min and 100 g tissue). The net coronary t-PA release was 68 ng X min-1 (30 ng X min-1 X 100 g"1)- Pulmonary net fluxes of t-PA were variable without any significant net t-PA release. The net hepatic uptake rate was 4,855 ng X min-1 (436 ng X min-1 X 100 g-1). Net trans-organ changes of active t-PA mirrored those of total t-PA. The results demonstrate marked regional differences in net release rates of t-PA in vivo. The experimental model we present offers new possibilities for evaluation of regional secretion patterns in the intact animal.